Liquids, such as water, are often used in an industrial process as the primary mechanism for heat transfer and regulation. In such processes, the liquid is often transported to and from the process center by way of a network of pipes. For example, in the field of metallurgical engineering, water is used to properly cool molten metal materials into desired forms.
When the temperature of a pipe or fluid cooled system component carrying a liquid such as water increases, the temperature of the liquid also increases. In the case of a copper pipe carrying water, because the melting point of copper is significantly higher than the boiling point of water, when the pipe or fluid cooled system component is exposed to too much heat the water will become steam, exerting a detectable pressure. If the temperature of the pipe becomes too great, the pipe or fluid cooled system component may melt or rupture, and allow the cooling liquid to leak in an undesired location, or prevent the liquid from reaching a necessary location. This generally necessitates the temporary cessation of the process until the damaged pipe or pipes or fluid cooled system components can be repaired. Such work stoppages are costly and inefficient and may cause product degradation.
There have been several attempts to address this issue. For example, U.S. Pat. No. 4,091,658 to Covington et al. discloses a system for measuring the pressure along fluid pipeline for the purposes of detecting leaks. It includes a pressure transducer for measuring pressure drops and logic to determine if there is a total drop in pressure or a pressure change which is beyond a preset limit. Covington et al. discloses shutting down a pipeline in instances of both inordinately low or high pressure conditions.
European patent No. 0559993 to Fanelli similarly discloses a system where pressure transducers are placed at various points along a pipe under pressure. Fanelli compares model values of the pressure flow to real values provided by the transducers, and produces an alarm signal when the comparison indicates a sudden loss of liquid due to a rupture of the pipeline.
U.S. Pat. No. 5,708,193 to Ledeen et al. proposes measuring pressure by creating a test pressure wave and detecting a reflecting wave of that test pressure wave using a pressure transducer. A digital filtering technique is used on the signal from the pressure transducer to permit detection of the location of a leak.
Likewise, U.S. Pat. No. 5,267,587 to Brown discloses an automatic monitoring system for utilities (i.e. water and gas). Brown proposes the use of pressure transducers to detect the pressure change of the utility, and solenoid valves to stop fluid (or gas) flow in the event that the pressure signal indicates unexpected leakage.
Unfortunately, the solutions disclosed by the prior art address situations where the system of pipes, or fluid cooled system components carrying the fluid has already failed. Accordingly, there exists a need for a technique for preventing a system of pipes or system components carrying a fluid from failing due to an overheating condition, in order to avoid the need to shut down the system and effect costly repairs.